Re: [ccp4bb] Precipitation issue during refolding

2017-09-26 Thread Hargreaves, David
issue during refolding Hi, I am working with a serine protease. As the protein is not soluble I am purifying it from the inclusion bodies followed by refolding. The protein shows good activity after refolding but the major concern is the 'precipitation'. Though the protein express

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Dipankar Manna
Thank you all for your valuable suggestions. I will try to improve the process accordingly. Best, Dipankar On Thu, Sep 21, 2017 at 3:18 PM, Tom Murray-Rust wrote: > Hi Dipankar, > > I've produced several serine protease constructs in Ecoli and then > refolded them. I would investigate the foll

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Tom Murray-Rust
Hi Dipankar, I've produced several serine protease constructs in Ecoli and then refolded them. I would investigate the following (some of which echoes previous comments): - try both urea and guanidine as your denaturant - try refolding in stages (e.g. 8M urea to 2M to 100mM or equivalent) - defin

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Debasish Kumar Ghosh
To: CCP4BB@JISCMAIL.AC.UK Sent: Thursday, September 21, 2017 3:42:28 PM Subject: [ccp4bb] Precipitation issue during refolding Hi, I am working with a serine protease. As the protein is not soluble I am purifying it from the inclusion bodies followed by refolding. The protein shows good acti

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Jared Sampson
Hi Dipankar - I will echo Thuy's suggestion of higher glycerol concentration in your refolding buffer. A protocol I used in a previous lab (for refolding antibody ScFv fragments) steps down gradually over 3 days from 10%-5%-0% glycerol in the dialysis buffer, from an initial sample of inclusi

[ccp4bb] AW: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Herman . Schreuder
Gesendet: Donnerstag, 21. September 2017 12:12 An: CCP4BB@JISCMAIL.AC.UK Betreff: [ccp4bb] Precipitation issue during refolding Hi, I am working with a serine protease. As the protein is not soluble I am purifying it from the inclusion bodies followed by refolding. The protein shows good activity

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Thuy Ngo
Dear Manna, I can see that you use only 5% glycerol in your buffer. This concentration is quite low for non-stable protein. I would suggest you to increase glycerol up to 20%. I had a case before that I need to use 30% glycerol in order to decrease the precipitation. Also, how did you do the re

Re: [ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Corbin Black
Hey Dipankar, There are various additives for improving solubility. I would consider some of these: - denaturants (ie urea, guanidine) - aggregation suppressors (arginine, low concentrations of urea, etc) - folding enhancers (sucrose, ammonium sulfate) And have you tried refolding your protein

[ccp4bb] Precipitation issue during refolding

2017-09-21 Thread Dipankar Manna
Hi, I am working with a serine protease. As the protein is not soluble I am purifying it from the inclusion bodies followed by refolding. The protein shows good activity after refolding but the major concern is the 'precipitation'. Though the protein express quite well, but I loose almost 50-60% p